Gum arabic

About: Gum arabic is a research topic. Over the lifetime, 2197 publications have been published within this topic receiving 47782 citations. The topic is also known as: acacia gum.

Purification, characterization and modification of gum arabic for possible use as additive for poly(vinyl chloride)

Abstract: Gum Arabic exudate was collected from Acacia senegal trees around Zaria metropolis, purified in 95% ethanol and its physical and chemical modifications carried out. Physical modification of the gum involved plasticization of the gum with glycerol and ethylene glycol. The chemical method was performed by acid hydrolysis, acetolysis and acetate formation. Appearance of both modifications was observed after three days of drying. Acetic anhydride (AAH), acetolysis (ACT) and ethylene glycol (EGL) modifications became hard and solid, and were ground to powder. Glycerol (GLY) turned very sticky and acid hydrolysis (AHY) turned into a viscous liquid. From characterization of the samples, all modifications were found to be less dense than the pure gum Arabic sample (PGM). AHY sample was found to be more turbid and has the highest conductivity value followed by AAH sample. pH of all samples was found to be below 7.0, indicating acidic nature of the gums. Melting point measurements showed that all test samples have lower melting point values than the pure gum. The viscosities of aqueous dispersions containing different concentrations of pure gum Arabic and that of the modified gums were determined. When concentration was varied for each gum, the viscosities of the solutions increased with increasing concentration. At each concentration the viscosity of AHY is far below that of the other samples, this is attributed to the fact that acid hydrolysis of polysaccharides normally breaks polysaccharides down to their monomers, dimers and some oligosaccharides FTIR spectra of the pure and chemically modified samples were studied. It was found that there were shifts and absorptions at different frequencies, indicating degree of interaction between the gum and the modifying solvents.

Underutilized Natural Gum and Resin Resources in Ethiopia for Future Directions and Commercial Utilization

Abstract: The drylands of Ethiopia are well known for their natural gum and resin producing tree and shrub species such as Acacia, Boswellia, Commiphora and Sterculia. The production and trade volumes of gums and resins in the country showed a declining trend since 2010. The present review work is focused on availability of alternative underutilized tree and shrub species to indicate the diverse gum and resin market opportunities. Several Sub-Saharan African countries are producing gum and resin products from diversified species. Gum arabic is collected from Acacia senegal (L) Willd, Acacia seyal DEL, and Acacia polyacantha Willd species. Three countries namely Sudan, Nigeria, Chad contribute about 97% to the international market, while Ethiopia's contribution is 0.9%. World demand for karaya gum from Sterculia setigera DEL is about 7,000 tonne and in Africa, Senegal is the leading exporter. Despite the huge resources of A. senegal, A. seyal and A. polyacantha, Ethiopia producing very low quantity, and gum is collected from natural oozes of trunks or branches. S. setigera is also found in the country, although gum karaya is not yet under production. South and south eastern parts of Ethiopia hosts abundant species of Acacia, Boswellia and Commiphora. Gum-resin products are collected from natural exudates by herdsmen, women and children while herding and doing other activities, indicating its adverse effects on quality and quantity. Very small proportions of Myrrh and gum opopanax enter the local market. Other constraints are, lack of appropriate institutions, infrastructure, tapping technologies and market information. Therefore, appropriate policy formulation, research and development interventions, are recommended for supporting sustainable management, production and marketing of products.

Effects of nitrogen, calcium and cation exchange capacity on gum yield in Acacia senegal under plantation and savanna woodland conditions in northern Guinea savanna, Nigeria

Abstract: Several reports have indicated fertilizer application is not required for increased gum yield in Acacia senegal. This study investigated the relationships between soil properties and gum yield under plantation and savanna woodland conditions. Multi-stage sampling was used to demarcate a 900 ha plantation into 20 blocks of 45 ha, and a 300 ha savanna woodland into 10 blocks of 30 ha. Twenty sub-plots per site were randomly selected for yield assessment by tapping for gum collection, weighing, and recording yield figures in grams. Twelve soil pits were established for soil analysis. Data were analyzed using log-log correlation, and linear regressions. Plantation results showed nitrogen (r = 0.72) and Cation Exchange Capacity (r = 0.67) were positively correlated with yield, and calcium and yield were negatively correlated (r = -0.73). The plantation results indicated the coefficient of determination (R2) and standard error (SE) were respectively 0.99 and 0.005 for nitrogen,0.79 and 0.024 for calcium, and 0.53 and 0.036 for CEC. Ninety-nine percent, 79%, and 53% of the variation in yield were explained by nitrogen, calcium and CEC, respectively. Under savanna woodland conditions, only nitrogen was positively correlated with yield (r = 0.65), and R2 and SE were respectively 0.70 and 0.014, with 70% of the variation in yield explained by nitrogen. Regression equations were subsequently developed to predict gum yield. Gum yield was correlated with soil chemical properties, and could be predicted based on nitrogen, calcium, and CEC values.